Voice control system for an implant

ABSTRACT

A system for the control of an implant ( 32 ) in a body ( 11 ), comprising first ( 10, 20 ) and second parts ( 12 ) which communicate with each other. The first part ( 10, 20 ) is adapted for implantation and for control of and communication with the medical implant ( 32 ), and the second part ( 12 ) is adapted to be worn on the outside of the body ( 11 ) in contact with the body and to receive control commands from a user and to transmit them to the first part ( 10, 20 ). The body ( 11 ) is used as a conductor for communication between the first ( 10, 20 ) and the second ( 12 ) parts. The second part ( 12 ) is adapted to receive and recognize voice control commands from a user and to transform them into signals which are transmitted to the first part ( 10, 20 ) via the body ( 11 ).

TECHNICAL FIELD

The present invention discloses a control system for an implant in amammal body, by means of which the implant can be controlled using voicecommands.

BACKGROUND

Medical implants as such are previously known, and are often used toreplace or assist an organ or a function in a mammal body. Some medicalimplants which may be mentioned by way of example are artificial hipjoints, pacemakers, artificial insulin pumps and the like.

As will be understood, some implants require, or may be improved by, theability to receive input from a user of the implant, either from thepatient or medical personnel attending to the patient. Various methodsare known for giving such input to implanted devices. For example, U.S.Pat. No. 5,569,186 to Snell et al discloses a glucose pump system, partsof which are implantable in a human body, where the operation of thesystem may be monitored and controlled from a monitor external to thehuman body, with the monitor being a wrist-worn device. The monitor ofthe Snell patent can display information from and send commands to therest of the system by means of telemetry signals, i.e. radio control.

SUMMARY

It is an object of the present invention to improve the comfort, easeand reliability with which a medical implant in a mammal body such as ahuman body may be controlled.

This object is achieved by the present invention in that it discloses asystem for the control of a medical implant in a mammal body. The systemof the invention comprises a first and a second part which are adaptedfor communication with each other; the first part is adapted forimplantation in the mammal body for the control of and communicationwith the medical implant, and the second part is adapted to be worn onthe outside of the mammal body in physical contact with said body.

In addition, the second part is adapted to receive control commands froma user and to transmit these commands to the first part, and the systemof the invention is adapted to use the mammal body as a conductor forcommunication between the first and the second parts.

Furthermore, the second part of the system is adapted to receive andrecognize control commands from a user as voice commands and is alsoadapted to transform recognized voice commands into signals which arethen transmitted to the first part via the mammal body as a conductorfor the control of said implant.

Thus, by means of the system of the invention, the user of an implant,or medical personnel or others who help the user, can control theimplant by means of spoken commands. In addition, the need for radiotransmitters etc as exhibited by other systems in the field of implantcontrol is obviated by means of the present invention, since the systemof the invention uses the body of the user as a conductor for thecommunication between the first and second parts of the implant.

The body is used as a conductor for communication by means of creatingan electrical (capacitive) field between the first and second parts ofthe system, which field may then be used for communicating between thetwo parts, by altering the field.

An alternative embodiment involves a system for the control of a medicalimplant (32) in a mammal body (11), said system comprising a first (10,20) and a second part (12) being adapted for communication with eachother, in which system the first part (10, 20) is adapted forimplantation in the mammal body (11) for the control of andcommunication with the medical implant (32), the second part (12) isadapted to be worn on the outside of the mammal body (11) in physicalcontact with said body and adapted to receive control commands from auser and to transmit these commands to the first part (10, 20),characterized in that the system is adapted to use the mammal body (11)as a conductor for communication between the first (10, 20) and thesecond (12) parts and in that the second part (12) is adapted to receiveand recognize the control commands from a user as voice commands and isadapted to transform recognized voice commands into signals which aretransmitted to the first part (10, 20) via the mammal body (11) as aconductor for the control of said implant (32), the first part (10, 20)being adapted to convey such signals to the implant (32), wherein saidsecond part (12) comprises a learning device adapted to successivelylearn the voice commands and learn to combine with the right outputcommand.

Yet another embodiment includes a system for the control of a medicalimplant (32) in a mammal body (11), said system comprising a first (10,20) and a second part (12) being adapted for communication with eachother, in which system the first part (10, 20) is adapted forimplantation in the mammal body (11) for the control of andcommunication with the medical implant (32), the second part (12) isadapted to be worn on the outside of the mammal body (11) in physicalcontact with said body and adapted to receive control commands from auser and to transmit these commands to the first part (10, 20),characterized in that the system is adapted to use the mammal body (11)as a conductor for communication between the first (10, 20) and thesecond (12) parts and in that the second part (12) is adapted to receiveand recognize the control commands from a user as voice commands and isadapted to transform recognized voice commands into signals which aretransmitted to the first part (10, 20) via the mammal body (11) as aconductor for the control of said implant (32), the first part (10, 20)being adapted to convey such signals to the implant (32), wherein saidvoice commands comprise a complex of different frequencies translatedinto one fixed defined output command, wherein said system comprising afirst conducting plate (29) in the first part (10, 20) of the system anda second conducting plate (27) in the second part (12) of the system,the system being adapted to create an electrical capacitive field withpotential differences between said first (29) and second (27) conductingplates.

The system may further comprise a detector circuit (30) in the firstpart (10, 20) of the system for detecting the potential differencesbetween the conducting plates (27, 29), the system being adapted to usethe potential differences for said communication between the first (10,20) and the second (12) parts of the system.

In an alternative embodiment of the system the second part (12)comprises a learning device adapted to successively learn the voicecommands and learn to combine with the right output command.

Preferable said learning device of the second part (12) is adapted torecognise approximate voice commands into a fixed defined outputcommand.

In yet another embodiment said voice commands comprise a complex ofdifferent frequencies translated into one fixed defined output command.

Preferably said output commands do not differentiate differentfrequencies, but instead summarise a defined input of differentfrequencies into one single action.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail in the following, withreference to the appended drawings, in which

FIG. 1 shows an overview of the system of the invention.

FIG. 2 shows a block diagram of a first embodiment.

FIG. 3 shows a circuit diagram of an embodiment.

FIGS. 4 and 5 show block diagrams of further embodiments.

FIGS. 6-8 show various embodiments of communication.

FIGS. 9-21 show embodiments of power sources for the first part of theinvention.

DETAILED DESCRIPTION

FIG. 1 shows an overview intended to illustrate the system of theinvention, and its use and application. As has been mentioned above, theinventive system is intended for use with a medical implant in a mammalbody, such as the human body, and FIG. 1 shows a human user 11 who hasbeen equipped with an implant 32. The implant 32 is shown in FIG. 1 asbeing located in the abdominal region of the user, but this is merely anexample intended to illustrate a generic implant with which theinvention can be used; such an implant can be located in more or lessany region of the mammal body, depending on the nature and function ofthe implant.

The implant 32 can be of various kinds, all of which are within thescope of the present invention, but examples of which mention may bemade include the following:

-   -   A controllable engine,    -   A pump,    -   A stimulation device,    -   A constriction device,    -   A fluid moving device,    -   A heart pump,    -   A heart valve,    -   A filtering device,    -   A pharmaceutical drug delivery device,    -   An artificial reservoir,    -   A fertility or non-fertility device,    -   A no-reflux device,    -   A potency treatment device,    -   A urine incontinence or urine retention device,    -   An intestinal device,    -   An aneurysm treatment device,    -   A hypertension treatment device,    -   A clot removing device

The system of the invention is adapted to control the implant 32, and tothis end the system comprises a first part 10 which is adapted forimplantation in the mammal body, and a second part 12 which is adaptedto be worn on the outside of the mammal body in physical contact withthe body.

As indicated in FIG. 1, the second part 12 is adapted to receive andrecognize control commands from a user in the form of voice commands(i.e. spoken commands), and to transform recognized voice commands intosignals which are transmitted to the first part 10. In other words, thesecond part 12 is adapted to recognize a number of spoken commands, suchas, for example, “more”, “less”, “on, “off”, “open”, “close”, and totransform these spoken commands into signals in a form which can betransmitted to and understood by the first part 10 of the system, i.e.the part which is implanted in the body 11.

The first part 10 is adapted to, upon receiving such commands from thesecond 12 part of the system, convey them to the implant 32 for controlof the implant.

According to the present invention, the second part 12 transmits thesignals (i.e. the control commands) to the first part 10 via the mammalbody 11 as a conductor, which is done by creating a capacitive fieldbetween the first 10 and the second 12 parts of the system, and thencreating variations in that field in order to use those variations forthe communication between the two parts of the system.

Below, various ways of creating the capacitive field will be described,and details will then be given on how the capacitive field andvariations in it can be used by the present invention for communicationbetween the two parts of the system. It should also be pointed out thatthe present invention makes use of the mammal body's conductingproperties for the communication: the electrical field which is createdwill propagate throughout the body due to the body's conductivity, andcan thus be created at one point in the body and detected at anotherpoint in the body. In a way, the body is thus used as an “antenna” orconductor by the present invention for the communication between the twoparts of the system.

An embodiment according to the combination of FIGS. 1 and 2, involves asystem for the control of a medical implant (32) in a mammal body (11),said system comprising a first (10, 20) and a second part (12) beingadapted for communication with each other, in which system the firstpart (10, 20) is adapted for implantation in the mammal body (11) forthe control of and communication with the medical implant (32), thesecond part (12) is adapted to be worn on the outside of the mammal body(11) in physical contact with said body and adapted to receive controlcommands from a user and to transmit these commands to the first part(10, 20). The system is adapted to use the mammal body (11) as aconductor for communication between the first (10, 20) and the second(12) parts and in that the second part (12) is adapted to receive andrecognize the control commands from a user as voice commands and isadapted to transform recognized voice commands into signals which aretransmitted to the first part (10, 20) via the mammal body (11) as aconductor for the control of said implant (32), the first part (10, 20)being adapted to convey such signals to the implant (32), wherein saidsecond part (12) comprise a learning device adapted to successivelylearn the voice commands and learn to combine with the right outputcommand.

Yet another embodiment includes a system for the control of a medicalimplant (32) in a mammal body (11), said system comprising a first (10,20) and a second part (12) being adapted for communication with eachother, in which system the first part (10, 20) is adapted forimplantation in the mammal body (11) for the control of andcommunication with the medical implant (32), the second part (12) isadapted to be worn on the outside of the mammal body (11) in physicalcontact with said body and adapted to receive control commands from auser and to transmit these commands to the first part (10, 20),characterized in that the system is adapted to use the mammal body (11)as a conductor for communication between the first (10, 20) and thesecond (12) parts and in that the second part (12) is adapted to receiveand recognize the control commands from a user as voice commands and isadapted to transform recognized voice commands into signals which aretransmitted to the first part (10, 20) via the mammal body (11) as aconductor for the control of said implant (32), the first part (10, 20)being adapted to convey such signals to the implant (32), wherein saidvoice commands comprise a complex of different frequencies translatedinto one fixed defined output command, wherein said system comprising afirst conducting plate (29) in the first part (10, 20) of the system anda second conducting plate (27) in the second part (12) of the system,the system being adapted to create an electrical capacitive field withpotential differences between said first (29) and second (27) conductingplates.

The system may further comprise a detector circuit (30) in the firstpart (10, 20) of the system for detecting the potential differencesbetween the conducting plates (27, 29), the system being adapted to usethe potential differences for said communication between the first (10,20) and the second (12) parts of the system.

In an alternative embodiment of the system the second part (12)comprises a learning device adapted to successively learn the voicecommands and learn to combine with the right output command.

Preferably the learning device of the second part (12) is adapted torecognise approximate voice commands into a fixed defined outputcommand.

In yet another embodiment said voice commands comprise a complex ofdifferent frequencies translated into one fixed defined output command.

Preferably said output commands do not differentiate differentfrequencies, but instead summarise a defined input of differentfrequencies into one single action.

FIG. 2 shows a block diagram of one embodiment of a system 20 of theinvention: a part of a mammal body is shown, with the skin indicted as aline 21. As shown in FIG. 2, the second part of the system 20, i.e. thepart which is intended to be worn on the outside of the mammal's body,comprises a device, symbolically shown as microphone 22, for detectingspoken commands from a user of the system, i.e. either the patient ore.g. medical personnel attending to the patient, which spoken commandsare intended to control a device 32 which has been implanted in thepatient.

In addition, the second part of the system 20 comprises a device 23 forrecognizing spoken commands, and for “translating” them into signals orcommands which can be understood by the implant 32. The signals orcommands which can be recognized by the implant 32 can vary depending onhow the implant 32 is designed, but can for example be commands in theform of ASCII characters, binary numbers etc.

For example, in order to illustrate this principle, assume a commandwhich indicates that the implant 32 should increase an activity which itcan perform. Assume further that the input to the implant 32 whichcauses the implant to increase this activity is “binary four”, i.e. 1 00; the recognition device 23 will then, when it recognizes the spokencommand “increase”, have as its output “binary four”, i.e. 1 0 0, whichcan then be transmitted to the implant 32 in a manner which will bedescribed below.

The recognition device 23 can in one embodiment be such that it is alearning device with a set number of output commands, or it can, if thetechnology permits, be such that it “understands” voice commands withoutany learning procedure. In either case, i.e. learning or non-learning,the recognition device is suitably “taught” by a user which spokencommand that should be matched to one of a set of commands which theimplant 32 can accept as input.

In the case of a learning device, then, in the example given above, withthe spoken command “increase”, the recognition device 23 will be exposedto this word from an authorized user a number of times; the recognitiondevice 23 indicates to the user that the word has been “learnt”, i.e.that the recognition device can recognize that particular word or phrasefrom that particular speaker in the future; the authorized user willthen match this word or phrase to the output “binary four”. The notionof “authorized user” is intended to prevent the system 20 of theinvention from outputting commands to the medical implant 32 when theyare spoken by non-authorized personnel. Naturally, a recognition devicewhich can recognize the same word or phrase from a set of authorizedusers can also be used within the scope of the present invention.

As is also shown in FIG. 2, the second part of the system 20 comprises asend/receive circuit 24 for generating the actual commands to theimplant 32. The second part also comprises a second capacitor plate 27which is connected (suitably by wire, as shown in FIG. 2) to thesend/receive device 24. As shown in FIG. 2, the first part of the systemalso comprises a first capacitor plate 29, which is implanted in thepatient since it is comprised in the first part of the system.

The second part of the system may also comprise a grounding plate 17,which is in close or direct contact with the mammal body 11.

According to the invention, the system 20 is adapted to create acapacitive field between the first and the second capacitive plates 29,27, and to create variations in this field by means of which commandscan be transmitted to the first part from the second part, and fromthere to the implanted device 32, which is connected to the first partof the system, suitably by wire, as indicated in FIG. 2, althoughwireless solutions are also within the scope of the invention.

A fact which is used by the present invention is that a mammal body willact as a conductor for a capacitive field, so that “signals” i.e.variations in the capacitive field will propagate between the two partsof the system by means of the body as a conductor.

Suitably, as shown in FIG. 2, one or both of the capacitive plates 27,29 are covered in a dielectric material 26, 28.

The second part of the system 20 also comprises a power supply 25, whichis shown in FIG. 2. Suitably but not necessarily this power supply 25 isa battery or some other form of portable power supply. The first partalso comprises a power supply, shown as 31 in FIG. 2. The power supply31 will be commented on in more depth later in this text.

Turning now to the first part of the system 20, i.e. the part which isintended to be implanted in the mammal patient and to be connected tothe medical implant 32 in order to transmit commands to it, and possiblyalso to receive signals from the implant 32 which are to be communicatedto the user of the implant, the first part comprises, as shown in FIG.2, the following major components: the capacitor plate 29, as describedabove, with a possible dielectric cover 28, and a receive (and possiblytransmit) device 30 connected to the capacitor plate 29 in order todetect the capacitive field and variations in it.

The first part also comprises a power supply 31, which will be describedin more detail below.

Turning now to more specific details of how a capacitive field can becreated by a system of the invention, and used by the system forcommunication between the first and second parts of the system, thefollowing can be said:

As has been pointed out previously in this text, the inventive systemuses the realization that by using the patient's body as a communicationmedium or conductor, and by creating and detecting (measuring)variations in a capacitive field, i.e. measuring the electric potentialin different places, communication between a first implanted part of thesystem and a second external (to the body) part, communication can beestablished with a minimum of electric current flowing through the body,and the communication can be used by the first implanted part forcontrolling and communicating with a medical implant.

Thus, for the communication of the invention, at least a portion of thepatient's body is used as a conductor. Generally, the internalcommunication unit, i.e. the first part of the system 20 comprises acommunication receiver, and for a transmitter or a transceiver 30 thatincludes one part of a capacitive energy storage. The communicating ofinformation using the capacitive coupling includes letting an electricalcurrent be injected into or drawn from the capacitive energy storage: Inthe system, the information can e.g. be represented as variations of thederivative of the voltage over the capacitive energy storage, i.e. astransitions in the voltage level.

The information may be coded according to the Manchester system, anddual frequency communication can be used.

With renewed reference to FIG. 2 and the system 20 shown there, as isshown at least one of the capacitor plates 27, 29, is embedded in anelectrical insulator, i.e. a dielectric material 26, 28, which suitablyforms a thin layer which totally surrounds the respective plate, theplates being made from an electrically conducting material, e.g. copper.The electrical resistance between the capacitor plates should be as highas possible, e.g. at least 1 MΩ.

The capacitor plates 27, 29 are electrically coupled to the transmitand/or receive circuits 24, 30, which can also be seen as “drivercircuits”, which basically can include transmitter and/or receivercircuits, or, where applicable, transceiver circuits. The drivercircuits 30 for the internal capacitor plate 29 are thus also adaptedfor implantation and for electrical connection to the implanted deviceor a control device therefore, shown as 32. The external driver circuits24 are connected to a control device, which is not shown in FIG. 2.

The driver circuits 24, 30 are powered by power supplies 25, 31, withthe internal power supply 31 also being adapted for implantation. Thedriver circuits may require a common electrical ground potential whichcan make the transfer of information more secure, which can be providedby e.g. having the housing of the internal driver circuits 30 beelectrically conducting, and thus in electrical contact with the bodytissues. The external driver circuits 24 can be electrically connectedto an electrically conducting plate or electrode 17 that is electricallyattached to the skin of the person's body in the same way as electrodesfor e.g. cardiography.

The capacitor formed by the capacitor plates 27, 29 is part of anelectric circuit connection between the driver circuits 24, 30, andelectrical signals can be transmitted over this circuit connection. Byselecting the dimensions of the plates and their location in relation toeach other, the capacitor which is thus formed can be given acapacitance suited for the signal transfer. Hence, the plates 27, 29 canbe made to have as large a surface area as is possible for an implant,e.g. in the range of 2-8 cm², and can be configured in a suitable way.Of course, the plates may also be rectangular or in the shape ofsquares, but they may also e.g. have an elongated round shape or acircular shape. In particular, the internal capacitor plate 29 can begiven a shape which makes it suitable to be implanted. Thus, it may e.g.have perforations or through-holes, not shown, for allowing it to besecurely attached to body tissues.

The driver circuits can be designed as is schematically illustrated inFIG. 3. FIG. 3 shows a circuit for both transmitting and receivinginformation, but it should be pointed out that the system of theinvention can also be a “one way” system, so that the second part issolely a transmitter, and the first part is solely a receiver. Thecircuit shown in FIG. 3 is “generic”, in that it may be used by eitherof the first and second part, with variations depending on whether ornot both parts of the system should be able to both transit and receiveinformation from the other part.

However, assuming a “two-way” system, as shown in FIG. 3, a capacitorplate 27, 29 is connected to a transmission stage 35 that includes atransmission output stage 36, which receives an input signal a wave oralternating electric signal from an oscillator circuit 37, e.g. avoltage controlled oscillator (VCO), with both the oscillator circuit 37and the transmission output stage 36 both being controlled by amicrocontroller 38 such as for commanding a special wave form and formodulating it, respectively.

The capacitor plate 27, 29 is also connected to a receiving stage 39that includes an amplifier 33 which also functions as a bandpass filter.The amplifier provides 33 its output signal to a signal detector 40which delivers the detected information signal to the microcontroller38. The driver circuits for the external and internal capacitor platescan include either of the transmission and receiving stages 35, 39, orboth of them, depending on the desired function. The microcontrollercan, for example, be of the type PIC16F818, and it thus controls thetransmission and receiving stage. For the “receive mode”, themicrocontroller converts the signal level received from the signaldetector 35, and then suitably uses an ADC such the on-chip 8-bit ADCbuilt into the PIC16F818.

As was shown in FIG. 1, in one embodiment, the second part of the system20, i.e. including the external capacitor plate 27 and its drivercircuits 24 and power supply 25 can be integrated in a device such as awristwatch 45. However, a wristwatch is merely one example of a devicein which the second part may be integrated; examples of other suchdevices are a necklace, a bracelet, a ring, an ear ring or a piercingornament for the human body, or a traditional watch.

In FIG. 2, the driver circuits 30, the power supply 31 and the internalcapacitor plate 29 are seen to be separate units, connected byelectrical cabling. These components can also be integrated as a singleunit, placed together inside a common enclosure or housing, which can bemade from an electrically insulating material which forms the electricalinsulation of the capacitor plate.

The communication channel or path having a capacitive coupling asdescribed above should have constant impedance, which should be as smallas possible in order to ensure that the communication signals areappropriately transferred. However, the capacitance of the capacitorused, having one capacitor plate 29 implanted in a patient's body maynot stay constant, due to, for example, the fact that the plates 27, 29can move in relation to each other, and that body functions in thetissues located between the capacitor plates can change. The frequencyused for the communication should be substantially constant, if e.g. acarrier signal which is modulated is used or pulses of a definitefrequency is used. Also, the frequency should suitably be as large aspossible, in order to make the impedance small.

In order to improve the total capacitive coupling between the capacitorplates 27, 29, the plates can be “divided” to each include a first plate27, 29 and a second plate 27′, 29′, as shown in FIG. 4, with the system20 being essentially similar otherwise to that shown in FIG. 2. Fortransmitting a signal from one part of the system to the other part ofthe system, the two plates on the sending side can be then provided withsignals which are the inverse of each other. Thus, e.g. the plate 27′can be provided with the direct signal and be denoted 27+ and the plate27 can be provided with the inverted signal, then be denoted 27−. Theinversion of signals can be easily achieved by arranging an invertercircuit in the transmission stage 21 of FIG. 2. In the receiving part,i.e. the first (implanted) part of the system, an inverter circuithaving the opposite direction can be used. The internal capacitor platemust be configured in a similar and corresponding way, having one plate29 for the direct signal and one plate 29′ for the inverted signal.

The dual capacitor plates used in this case can for ease of positioningbe configured as concentric circular fields, as shown in FIG. 5, atleast one of which is annular. One capacitor portion 27+, 29+ can e.g.be a central circular field that is surrounded by an annular circularfield 27−, 29−.

Various ways of communicating signals over the communication pathinvolving a capacitive coupling can be conceived, considering the abovementioned conditions of the signal transmission; some possible methodswill now be described.

In the simplest case, the signals used in the communication between theexternal and internal devices can e.g. be electric pulses, e.g.substantially rectangular pulses. However, since the communication ofinformation in most case must be made with a high degree of security, asuitable coding of the information could be used. Hence, e.g. Manchestercoding can be used.

Manchester encoding is a special case of binary phase shift keying whereeach bit of data is signified by at least one transition. The encodingis therefore self-clocking which makes accurate synchronization of thedata stream possible. For example, a “1” can be represented by atransition from a high to a low level and a “0” can be represented by atransition from a low to a high electrical level. This means that in thederivative of the electrical signal, there are variations so that a “1”can be seen as a negative pulse and a “0” as a positive pulse. In theelectrical signal there are also transitions between the two levels thatdo not represent any information but are necessary in order that thetransitions representing information can be arranged in the electrical,such extra transitions thus inserted when sending two equal consecutivebits of information.

For the case of simple pulse transmission, the transmitter output stage36 and the oscillator 37 illustrated in the circuit diagram of FIG. 3may not be required since the pulses can be generated directly in themicroprocessor 38 and provided to the respective capacitor plate 27, 29.A typical Manchester encoded signal generated by a microcontroller isillustrated in the diagram of FIG. 6.

FIG. 7 is a circuit diagram of driver circuits 24, 30 comprising atransceiver that can be used in this case.

For receiving, the transmitted signal is picked up by the capacitorplate 27, 29. The DC level of the signal is by the resistor R22 pulledto 2.5V which is equal to VCC/2. The received signal is provided to apreamplifier stage 51 including an amplifier U9 before it is passed tofilter stages. The amplifier has a high input impedance and a low biascurrent. The signal is then provided to a high pass filter stage 53 thatis configured as a second order active high pass filter including anamplifier U10 as its active element. This filter stage removes lowfrequency interfering signals and noise. Then, the signal is passed to alow pass filter stage 55 being a passive filter of RC-type, comprising aresistor R41 and a capacitor C8 to remove high frequency noise.

The signal is then provided to a signal detector stage that here isdesigned as a comparator 57 stage having hysteresis. Thus, the receivedand filtered signal is fed to the inverting input of a comparator U7.The same signal is also first even more low pass filtered in a passiveRC-filter including R41 and C14 and then fed to the non-inverting inputof the comparator via a resistor R6. The resistor R6 and the feedbackresistor R12 form the hysteresis feedback. The comparator U7 hashysteresis in order to output a square wave in Manchester code even ifthe signal drops down below the DC level. An example of a received andfilter signal can be seen in FIG. 6 b and the output from the comparatorU7 in FIG. 6 c.

The microcontroller U19 is used to decode the received Manchester streaminto useful data. This is achieved by measuring the time between risingand falling edges. When a reception is initialized, the microcontrollerreceives a preamble consisting of the repeated pattern “10101010”. Sincethe only transitions that occur in that pattern are the bit transitionsthe preamble can be used to synchronize the data, i.e. to form a clocksignal. When synchronization has been accomplished, the microcontrollercan begin to translate the Manchester stream into useful data.

Another method is to use amplitude modulation to transfer data. Forinstance, a carrier frequency can be on/off-modulated to output burstsof the electrical signal.

For this method, driver circuits like those illustrated in FIG. 8 mayfor instance be used. The transmission stage 21 has a signal generatorU22 that can be enabled by a signal “OSC_POW” from the microcontrollerU19 in the microcontroller stage, the signal opening a transistor U4.The signal generator U22 outputs a oscillatory signal having a frequencyof about 1.4 MHz that is set by the resistors R30 and R54. The outputfrom the signal generator U22 is fed to the gate of another transistorU3. Another signal “OSC_EN” from the microcontroller is used to modulatethe amplitude of the signal by being provided the gate of a transistorU2. The transistor U2 and resistor R43 are provided to make it possibleto transmit a voltage higher than 5V.

For receiving information, the transmitted signal is picked up by thecapacitor plate connected to J4. The DC level of the received signal isby the resistor 22 pulled to 2.5V which is equal to VCC/2. The receivedis provided to a preamplifier stage 61 including an amplifier U9 havinga high input impedance and a low bias current. The amplified signal ispassed to a bandpass filter 63. The bandpass filter is a second orderactive band pass filter including an amplifier U10 as its activeelement.

The filtered signal is provided to a variable gain amplifier 65including a non-inverting amplifier U13. A resistor connects theinverting input of the non-inverting amplifier to a reference voltagethat can be chosen by setting an analogue switch U17. The gain of thevariable gain amplifier 65 can therefore be set by the microcontroller27 by control signals “VGA1-4”. After having passed the variable gainamplifier, the signal is half-wave rectified in a rectifier stage 67including an the amplifier U18 having two diodes D14 connected in itsfeedback loop. The rectified signal is by a passive low pass RC-filter69 including a resistor R50 and a capacitor C28 to output a rectangularwave. The rectangular wave is high when the amplitude of the receivedsignal is high or on and it is low when the amplitude is off or zero.

Finally, the desired signal is detected in a signal detector orcomparator stage 35 by being provided to the non-inverting input of acomparator U21. The signal is also simultaneously low pass filtered bythe RC-filter arranged by the resistor R52 and the capacitor C40 toprovide an averaged signal to the inverting input. The signal “DATA”output from the comparator U21 is fed to the microcontroller 27 todecode the received data.

For the data reception to work properly in this case it may be importantthat the transmitted signal is balanced in the meaning that it is on andoff for the same amount of time. The data can for that reason, also inthis case, be encoded using Manchester code as described above.

A development of the simple amplitude modulation method using a carriedthat is switched on and off is the method called frequency shift keying(FSK). This modulation scheme represents a digital ‘0’ with a firstfrequency and a ‘1’ with a second, different frequency where thesefrequencies can be selected to be as large as possible. If possible,also rectangular waves can be used instead of sine waves to get a bettertransmission through the capacitive link.

In demodulating, in this case a received frequency is transformed into a‘0’ or ‘1’. This can be done using a phase locked loop (PLL), inparticular a digital phase locked loop (DPLL). Such a digitaldemodulating circuit comprises a pfd or phase detector, a loop filter, aVCO counter and a decider. The phase detector looks on the incomingsignal and compares it to the generated signal in the VCO counter. Ifany of the signals goes high before the other, this information is sentto the loop filter. The loop filter gets the information about whichsignal goes high first and translates this to a control signal for theVCO counter. This signal is the preset for the counter inside VCOcounter. The VCO counter is a counter that always counts down and has aload and preset inputs. These inputs are controlled by the loop filter.

The decider is a unit or circuit which creates the data signal. This isdone by looking at the preset signals and, depending on the value,choosing between a ‘0’ and ‘1’.

Turning now to how energy is supplied to the parts of the inventivesystem 20, this has been hinted at in FIGS. 2 and 4, by means of thepower supplies 25 and 31 shown there. The second part, i.e. the partwhich is adapted to be worn externally to the mammal body can be poweredin a number of ways, such as batteries, rechargeable accumulators etc,but the power supply of the first part, i.e. the part which is adaptedfor implantation in a mammal body naturally presents a bigger challenge.In the following, a number of suitable alternative or complementary waysof powering the first part of the inventive system will be described.

The first part 10 of the system will also be referred to below as “theapparatus”.

FIG. 9 illustrates one embodiment of a system 300 for supplying thefirst part 10 of the present invention with energy. The first part 10is, by way of example, in FIG. 9 shown as being placed in the abdomen ofa patient; the implant which is to be controlled via the first part 10is not shown in FIG. 9.

In one embodiment, an implantable energy-transforming device 302 isadapted to supply energy consuming components of the apparatus 10 withenergy via a power supply line 303. An external energy-transmissiondevice 304 for non-invasively energizing the apparatus 10 transmitsenergy to the implantable energy-transforming device 302 by at least onewireless energy signal. The implanted energy-transforming device 302transforms energy from the wireless energy signal into electrical energywhich is supplied via the power supply line 303.

The wireless energy signal may include a wave signal selected from thefollowing: a sound wave signal, an ultrasound wave signal, anelectromagnetic wave signal, an infrared light signal, a visible lightsignal, an ultra violet light signal, a laser light signal, a micro wavesignal, a radio wave signal, an x-ray radiation signal and a gammaradiation signal. Alternatively, the wireless energy signal may includean electric or magnetic field, or a combined electric and magneticfield.

The wireless energy-transmission device 304 may transmit a carriersignal for carrying the wireless energy signal. Such a carrier signalmay include digital, analogue or a combination of digital and analoguesignals. In this case, the wireless energy signal includes an analogueor a digital signal, or a combination of an analogue and digital signal.

Generally speaking, the energy-transforming device 302 is provided fortransforming wireless energy of a first form transmitted by theenergy-transmission device 304 into energy of a second form, whichtypically is different from the energy of the first form. The implantedapparatus 10 is operable in response to the energy of the second form.The energy-transforming device 302 may directly power the apparatus withthe second form energy, as the energy-transforming device 302 transformsthe first form energy transmitted by the energy-transmission device 304into the second form energy. The system may further include animplantable accumulator, wherein the second form energy is used at leastpartly to charge the accumulator.

Alternatively, the wireless energy transmitted by theenergy-transmission device 304 may be used to directly power theapparatus 10, as the wireless energy is being transmitted by theenergy-transmission device 304. Where the system comprises an operationdevice for operating the apparatus, as will be described below, thewireless energy transmitted by the energy-transmission device 304 may beused to directly power the operation device to create kinetic energy forthe operation of the apparatus.

The wireless energy of the first form may comprise sound waves and theenergy-transforming device 302 may include a piezo-electric element fortransforming the sound waves into electric energy. The energy of thesecond form may comprise electric energy in the form of a direct currentor pulsating direct current, or a combination of a direct current andpulsating direct current, or an alternating current or a combination ofa direct and alternating current. Normally, the apparatus compriseselectric components that are energized with electrical energy. Otherimplantable electric components of the system may be at least onevoltage level guard or at least one constant current guard connectedwith the electric components of the apparatus.

Optionally, one of the energy of the first form and the energy of thesecond form may comprise magnetic energy, kinetic energy, sound energy,chemical energy, radiant energy, electromagnetic energy, photo energy,nuclear energy or thermal energy. Preferably, one of the energy of thefirst form and the energy of the second form is non-magnetic,non-kinetic, non-chemical, non-sonic, non-nuclear or non-thermal.

The energy-transmission device may be controlled from outside thepatient's body to release electromagnetic wireless energy, and thereleased electromagnetic wireless energy is used for operating theapparatus. Alternatively, the energy-transmission device is controlledfrom outside the patient's body to release non-magnetic wireless energy,and the released non-magnetic wireless energy is used for operating theapparatus. Naturally, the energy-transmission device can also becontrolled by the communication between the first 10 and the secondparts 12 of the invention.

The external energy-transmission device 304 can also, in one embodiment,include a wireless remote control having an external signal transmitterfor transmitting a wireless control signal for non-invasivelycontrolling the apparatus. The control signal is received by animplanted signal receiver which may be incorporated in the implantedenergy-transforming device 302 or be separate there from.

The wireless control signal may include a frequency, amplitude, or phasemodulated signal or a combination thereof. Alternatively, the wirelesscontrol signal includes an analogue or a digital signal, or acombination of an analogue and digital signal. Alternatively, thewireless control signal comprises an electric or magnetic field, or acombined electric and magnetic field.

The wireless remote control may transmit a carrier signal for carryingthe wireless control signal. Such a carrier signal may include digital,analogue or a combination of digital and analogue signals. Where thecontrol signal includes an analogue or a digital signal, or acombination of an analogue and digital signal, the wireless remotecontrol preferably transmits an electromagnetic carrier wave signal forcarrying the digital or analogue control signals.

FIG. 10 illustrates the system of FIG. 9 in the form of a moregeneralized block diagram showing the apparatus 10, theenergy-transforming device 302 powering the apparatus 10 via powersupply line 303, and the external energy-transmission device 304, Thepatient's skin 305, generally shown by a vertical line, separates theinterior of the patient to the right of the line from the exterior tothe left of the line.

FIG. 11 shows an embodiment of the invention identical to that of FIG.10, except that a reversing device in the form of an electric switch 306operable for example by polarized energy also is implanted in thepatient for reversing the apparatus 10. When the switch is operated bypolarized energy the wireless remote control of the externalenergy-transmission device 304 transmits a wireless signal that carriespolarized energy and the implanted energy-transforming device 302transforms the wireless polarized energy into a polarized current foroperating the electric switch 306. When the polarity of the current isshifted by the implanted energy-transforming device 302 the electricswitch 306 reverses the function performed by the apparatus 10.

In all of the embodiments described herein, the energy-transformingdevice 302 may include a rechargeable accumulator like a battery or acapacitor to be charged by the wireless energy and supplies energy forany energy consuming part of the system.

FIG. 12 shows an embodiment of the invention comprising the externalenergy-transmission device 304, the apparatus 10, the implantedenergy-transforming device 302, an implanted internal control unit 315controlled by the wireless remote control of the externalenergy-transmission device 304, an implanted accumulator 316 and animplanted capacitor 317.

The internal control unit 315 arranges storage of electric energyreceived from the implanted energy-transforming device 302 in theaccumulator 316, which supplies energy to the apparatus 10. In responseto a control signal from the wireless remote control of the externalenergy-transmission device 304, the internal control unit 315 eitherreleases electric energy from the accumulator 316 and transfers thereleased energy via power lines 318 and 319, or directly transferselectric energy from the implanted energy-transforming device 302 via apower line 320, the capacitor 317, which stabilizes the electriccurrent, a power line 321 and the power line 319, for the operation ofthe apparatus 10.

The internal control unit is preferably programmable from outside thepatient's body. In a preferred embodiment, the internal control unit isprogrammed to regulate the apparatus 10 according to a pre-programmedtime-schedule or to input from any sensor sensing any possible physicalparameter of the patient or any functional parameter of the system.

In accordance with an alternative, the capacitor 317 in the embodimentof FIG. 12 may be omitted. In accordance with another alternative, theaccumulator 316 in this embodiment may be omitted.

FIG. 13 shows an embodiment of the invention identical to that of FIG.10, except that a battery 322 for supplying energy for the operation ofthe apparatus 10 and an electric switch 323 for switching the operationof the apparatus 10 are also implanted in the patient. The electricswitch 323 may be controlled by the remote control and may also beoperated by the energy supplied by the implanted energy-transformingdevice 302 to switch from an off mode, in which the battery 322 is notin use, to an on mode, in which the battery 322 supplies energy for theoperation of the apparatus 10.

FIG. 14 shows an embodiment of the invention identical to that of FIG.13, except that an internal control unit 315 controllable by a wirelessremote control of the external energy-transmission device 304 also isimplanted in the patient. In this case, the electric switch 323 isoperated by the energy supplied by the implanted energy-transformingdevice 302 to switch from an off mode, in which the wireless remotecontrol is prevented from controlling the internal control unit 315 andthe battery is not in use, to a standby mode, in which the remotecontrol is permitted to control the internal control unit 315 to releaseelectric energy from the battery 322 for the operation of the apparatus10.

FIG. 15 shows an embodiment of the invention identical to that of FIG.14, except that an accumulator 316 is substituted for the battery 322and the implanted components are interconnected differently. In thiscase, the accumulator 316 stores energy from the implantedenergy-transforming device 302. In response to a control signal from thewireless remote control of the external energy-transmission device 304,the internal control unit 315 controls the electric switch 323 to switchfrom an off mode, in which the accumulator 316 is not in use, to an onmode, in which the accumulator 316 supplies energy for the operation ofthe apparatus 10. The accumulator may be combined with or replaced by acapacitor.

FIG. 16 shows an embodiment of the invention identical to that of FIG.15, except that a battery 322 also is implanted in the patient and theimplanted components are interconnected differently. In response to acontrol signal from a wireless remote control of the externalenergy-transmission device 304, the internal control unit 315 controlsthe accumulator 316 to deliver energy for operating the electric switch323 to switch from an off mode, in which the battery 322 is not in use,to an on mode, in which the battery 322 supplies electric energy for theoperation of the apparatus 10.

Alternatively, the electric switch 323 may be operated by energysupplied by the accumulator 316 to switch from an off mode, in which thewireless remote control is prevented from controlling the battery 322 tosupply electric energy and is not in use, to a standby mode, in whichthe wireless remote control is permitted to control the battery 322 tosupply electric energy for the operation of the apparatus 10.

It should be understood that the switch 323 and all other switches inthis application should be interpreted in its broadest embodiment. Thismeans a transistor, MCU, MCPU, ASIC, FPGA or a DA converter or any otherelectronic component or circuit that may switch the power on and off.Preferably the switch is controlled from outside the body, oralternatively by an implanted internal control unit.

FIG. 17 shows an embodiment of the invention identical to that of FIG.14 except that the implanted components are interconnected differently.Thus, in this case, the internal control unit 315 is powered by thebattery 322 when the accumulator 316, suitably a capacitor, activatesthe electric switch 323 to switch to an “on” mode. When the electricswitch 323 is in its “on” mode, the internal control unit 315 ispermitted to control the battery 322 to supply, or not supply, energyfor the operation of the apparatus 10.

FIG. 18 schematically shows conceivable combinations of implantedcomponents of the apparatus for achieving various communication options.Basically, there is the apparatus 10, the internal control unit 315, anoptional component 309, and the external energy-transmission device 304including the external wireless remote control. As already describedabove, a wireless remote control transmits a control signal which isreceived by the internal control unit 315, which in turn controls thevarious implanted components of the apparatus.

The internal control unit 315, or alternatively the external wirelessremote control of the external energy-transmission device 304, maycontrol the apparatus 10 in response to signals from the sensor 325. Atransceiver may be combined with the sensor 325 for sending informationon the sensed physical parameter to the external wireless remotecontrol. The wireless remote control may comprise a signal transmitteror transceiver and the internal control unit 315 may comprise a signalreceiver or transceiver.

Alternatively, the wireless remote control may comprise a signalreceiver or transceiver and the internal control unit 315 may comprise asignal transmitter or transceiver. The above transceivers, transmittersand receivers may be used for sending information or data related to theapparatus 10 from inside the patient's body to the outside thereof.

Where the battery 322 for powering the apparatus 10 is implanted,information related to the charging of the battery 322 may be fed back.To be more precise, when charging a battery or accumulator with energy,feedback information related to said charging process is sent and theenergy supply is changed accordingly. This information is suitably sentvia the communication between the first and second parts of theinventive system.

An internal energy receiver can be adapted to directly or indirectlysupply received energy to the energy consuming components of theapparatus 10 via a switch 326. An energy balance is determined betweenthe energy received by the internal energy receiver 302 and the energyused for the apparatus 10, and the transmission of wireless energy isthen controlled based on the determined energy balance. The energybalance thus provides an accurate indication of the correct amount ofenergy needed, which is sufficient to operate the apparatus 10 properly,but without causing undue temperature rise.

In FIGS. 10-17, the patient's skin is indicated by a vertical line 305.Here, the energy receiver comprises an energy-transforming device 302located inside the patient, preferably just beneath the patient's skin305. Generally speaking, the implanted energy-transforming device 302may be placed in the abdomen, thorax, muscle fascia (e.g. in theabdominal wall), subcutaneously, or at any other suitable location. Theimplanted energy-transforming device 302 is adapted to receive wirelessenergy E transmitted from the external energy-source 304 a provided inan external energy-transmission device 304 located outside the patient'sskin 305 in the vicinity of the implanted energy-transforming device302.

As is well known in the art, the wireless energy E may generally betransferred by means of any suitable Transcutaneous Energy Transfer(TET) device, such as a device including a primary coil arranged in theexternal energy source 304 a and an adjacent secondary coil arranged inthe implanted energy-transforming device 302. When an electric currentis fed through the primary coil, energy in the form of a voltage isinduced in the secondary coil which can be used to power the implantedenergy consuming components of the apparatus, e.g. after storing theincoming energy in an implanted energy source, such as a rechargeablebattery or a capacitor.

However, the present invention is generally not limited to anyparticular energy transfer technique, TET devices or energy sources, andany kind of wireless energy may be used. The amount of energy receivedby the implanted energy receiver may be compared with the energy used bythe implanted components of the apparatus. The term “energy used” isthen understood to include also energy stored by implanted components ofthe apparatus.

A control device includes an external control unit that controls theexternal energy source 304 a based on the determined energy balance toregulate the amount of transferred energy. In order to transfer thecorrect amount of energy, the energy balance and the required amount ofenergy is determined by means of a determination device including animplanted internal control unit 315 connected between the switch 326 andthe apparatus 10. The internal control unit 315 may thus be arranged toreceive various measurements obtained by suitable sensors or the like,not shown, measuring certain characteristics of the apparatus 10,somehow reflecting the required amount of energy needed for properoperation of the apparatus 10.

Moreover, the current condition of the patient may also be detected bymeans of suitable measuring devices or sensors, in order to provideparameters reflecting the patient's condition. Hence, suchcharacteristics and/or parameters may be related to the current state ofthe apparatus 10, such as power consumption, operational mode andtemperature, as well as the patient's condition reflected by parameterssuch as; body temperature, blood pressure, heartbeats and breathing.Other kinds of physical parameters of the patient and functionalparameters of the device are described elsewhere.

Furthermore, an energy source in the form of an accumulator 316 mayoptionally be connected to the implanted energy-transforming device 302via the control unit 315 for accumulating received energy for later useby the apparatus 10. Alternatively or additionally, characteristics ofsuch an accumulator, also reflecting the required amount of energy, maybe measured as well. The accumulator may be replaced by a rechargeablebattery, and the measured characteristics may be related to the currentstate of the battery, any electrical parameter such as energyconsumption voltage, temperature, etc. In order to provide sufficientvoltage and current to the apparatus 10, and also to avoid excessiveheating, it is clearly understood that the battery should be chargedoptimally by receiving a correct amount of energy from the implantedenergy-transforming device 302, i.e. not too little or too much. Theaccumulator may also be a capacitor with corresponding characteristics.

For example, battery characteristics may be measured on a regular basisto determine the current state of the battery, which then may be storedas state information in a suitable storage means in the internal controlunit 315. Thus, whenever new measurements are made, the stored batterystate information can be updated accordingly. In this way, the state ofthe battery can be “calibrated” by transferring a correct amount ofenergy, so as to maintain the battery in an optimal condition.

Thus, the internal control unit 315 of the determination device isadapted to determine the energy balance and/or the currently requiredamount of energy, (either energy per time unit or accumulated energy)based on measurements made by the above-mentioned sensors or measuringdevices of the apparatus 10, or the patient, or an implanted energysource if used, or any combination thereof. The internal control unit315 is further connected to an internal signal transmitter 327, arrangedto transmit a control signal reflecting the determined required amountof energy, to an external signal receiver 304 c connected to theexternal control unit 304 b. The amount of energy transmitted from theexternal energy source 304 a may then be regulated in response to thereceived control signal.

Alternatively, the determination device may include the external controlunit 304 b. In this alternative, sensor measurements can be transmitteddirectly to the external control unit 304 b wherein the energy balanceand/or the currently required amount of energy can be determined by theexternal control unit 304 b, thus integrating the above-describedfunction of the internal control unit 315 in the external control unit304 b. In that case, the internal control unit 315 can be omitted andthe sensor measurements are supplied directly to the internal signaltransmitter 327 which sends the measurements over to the external signalreceiver 304 c and the external control unit 304 b. The energy balanceand the currently required amount of energy can then be determined bythe external control unit 304 b based on those sensor measurements.

Hence, the present solution can employ the feedback of informationindicating the required energy, which is more efficient than many othersolutions since it is based on the actual use of energy that is comparedto the received energy, e.g. with respect to the amount of energy, theenergy difference, or the energy receiving rate as compared to theenergy rate used by implanted energy consuming components of theapparatus. The apparatus may use the received energy either forconsuming or for storing the energy in an implanted energy source or thelike. The different parameters discussed above would thus be used ifrelevant and needed and then as a tool for determining the actual energybalance. However, such parameters may also be needed per se for anyactions taken internally to specifically operate the apparatus.

Thus, the feedback information may be transferred either by a separatecommunication system including receivers and transmitters or may beintegrated in the energy system, or by means of the communicationbetween the first and the second part of the system. In accordance withone embodiment of the present invention, such an integrated informationfeedback and energy system comprises an implantable internal energyreceiver for receiving wireless energy, the energy receiver having aninternal first coil and a first electronic circuit connected to thefirst coil, and an external energy transmitter for transmitting wirelessenergy, the energy transmitter having an external second coil and asecond electronic circuit connected to the second coil.

The external second coil of the energy transmitter transmits wirelessenergy which is received by the first coil of the energy receiver. Thisembodiment of the inventive system further comprises a power switch forswitching the connection of the internal first coil to the firstelectronic circuit on and off, such that feedback information related tothe charging of the first coil is received by the external energytransmitter in the form of an impedance variation in the load of theexternal second coil, when the power switch switches the connection ofthe internal first coil to the first electronic circuit on and off. Inimplementing this embodiment of the system, the switch is eitherseparate and controlled by the internal control unit 315, or integratedin the internal control unit 315. It should be understood that theswitch 326 should be interpreted in its broadest embodiment. This meansa transistor, MCU, MCPU, ASIC FPGA or a DA converter or any otherelectronic component or circuit that may switch the power on and off.

To conclude, this embodiment of the energy supply arrangement mayoperate basically in the following manner: The energy balance is firstdetermined by the internal control unit 315 of the determination device.A control signal reflecting the required amount of energy is alsocreated by the internal control unit 315, and the control signal istransmitted from the internal signal transmitter 327 to the externalsignal receiver 304 c. Alternatively, the energy balance can bedetermined by the external control unit 304 b instead depending on theimplementation, as mentioned above. In that case, the control signal maycarry measurement results from various sensors.

The amount of energy emitted from the external energy source 304 a canthen be regulated by the external control unit 304 b, based on thedetermined energy balance, e.g. in response to the received controlsignal. This process may be repeated intermittently at certain intervalsduring ongoing energy transfer, or may be executed on a more or lesscontinuous basis during the energy transfer.

The amount of transferred energy can generally be regulated by adjustingvarious transmission parameters in the external energy source 304 a,such as voltage, current, amplitude, wave frequency and pulsecharacteristics.

This system may also be used to obtain information about the couplingfactors between the coils in a TET system even to calibrate the systemboth to find an optimal place for the external coil in relation to theinternal coil and to optimize energy transfer. Simply comparing in thiscase the amount of energy transferred with the amount of energyreceived. For example if the external coil is moved the coupling factormay vary and correctly displayed movements could cause the external coilto find the optimal place for energy transfer. Preferably, the externalcoil is adapted to calibrate the amount of transferred energy to achievethe feedback information in the determination device, before thecoupling factor is maximized.

This coupling factor information may also be used as a feedback duringenergy transfer. In such a case, the energy system of the presentinvention comprises an implantable internal energy receiver forreceiving wireless energy, the energy receiver having an internal firstcoil and a first electronic circuit connected to the first coil, and anexternal energy transmitter for transmitting wireless energy, the energytransmitter having an external second coil and a second electroniccircuit connected to the second coil.

The external second coil of the energy transmitter transmits wirelessenergy which is received by the first coil of the energy receiver. Thissystem further comprises a feedback device for communicating out theamount of energy received in the first coil as a feedback information,and wherein the second electronic circuit includes a determinationdevice for receiving the feedback information and for comparing theamount of transferred energy by the second coil with the feedbackinformation related to the amount of energy received in the first coilto obtain the coupling factor between the first and second coils. Theenergy transmitter may regulate the transmitted energy in response tothe obtained coupling factor.

With reference to FIG. 19, although wireless transfer of energy foroperating the apparatus has been described above to enable non-invasiveoperation, it will be appreciated that the apparatus can be operatedwith wire bound energy as well. Such an example is shown in FIG. 20,wherein an external switch 326 is interconnected between the externalenergy source 304 a and an operation device, such as an electric motor307 operating the apparatus 10. An external control unit 304 b controlsthe operation of the external switch 326 to effect proper operation ofthe apparatus 10.

FIG. 20 illustrates different embodiments for how received energy can besupplied to and used by the apparatus 10. Similar to the example of FIG.19, an internal energy receiver 302 receives wireless energy E from anexternal energy source 304 a which is controlled by a transmissioncontrol unit 304 b. The internal energy receiver 302 may comprise aconstant voltage circuit, indicated as a dashed box “constant V” in thefigure, for supplying energy at constant voltage to the apparatus 10.The internal energy receiver 302 may further comprise a constant currentcircuit, indicated as a dashed box “constant C” in the figure, forsupplying energy at constant current to the apparatus 10.

The apparatus 10 comprises an energy consuming part 10 a, that requiresenergy for its electrical operation. The apparatus 10 may furthercomprise an energy storage device 10 b for storing energy supplied fromthe internal energy receiver 302. Thus, the supplied energy may bedirectly consumed by the energy consuming part 10 a, or stored by theenergy storage device 10 b, or the supplied energy may be partlyconsumed and partly stored. The apparatus 10 may further comprise anenergy stabilizing unit 10 c for stabilizing the energy supplied fromthe internal energy receiver 302. Thus, the energy may be supplied in afluctuating manner such that it may be necessary to stabilize the energybefore consumed or stored.

The energy supplied from the internal energy receiver 302 may further beaccumulated and/or stabilized by a separate energy stabilizing unit 328located outside the apparatus 10, before being consumed and/or stored bythe apparatus 10. Alternatively, the energy stabilizing unit 328 may beintegrated in the internal energy receiver 302. In either case, theenergy stabilizing unit 328 may comprise a constant voltage circuitand/or a constant current circuit.

It should be noted that FIG. 19 and FIG. 20 illustrate some possible butnon-limiting implementation options regarding how the various shownfunctional components and elements can be arranged and connected to eachother. However, the skilled person will readily appreciate that manyvariations and modifications can be made within the scope of the presentinvention.

FIG. 21 schematically shows an energy balance measuring circuit of oneof the proposed designs of the system for controlling transmission ofwireless energy, or energy balance control system. The circuit has anoutput signal centered on 2.5V and proportionally related to the energyimbalance. The derivative of this signal shows if the value goes up anddown and how fast such a change takes place. If the amount of receivedenergy is lower than the energy used by implanted components of theapparatus, more energy is transferred and thus charged into the energysource.

The output signal from the circuit is typically feed to an A/D converterand converted into a digital format. The digital information can then besent to the external energy-transmission device allowing it to adjustthe level of the transmitted energy. Another possibility is to have acompletely analog system that uses comparators comparing the energybalance level with certain maximum and minimum thresholds sendinginformation to external energy-transmission device if the balance driftsout of the max/min window.

The schematic FIG. 21 shows a circuit implementation for a system thattransfers energy to the implanted energy components of the apparatus ofthe present invention from outside of the patient's body using inductiveenergy transfer. An inductive energy transfer system typically uses anexternal transmitting coil and an internal receiving coil.

The implementation of the general concept of energy balance and the waythe information is transmitted to the external energy transmitter can ofcourse be implemented in numerous different ways. The schematic FIG. 23and the above described method of evaluating and transmitting theinformation should only be regarded as examples of how to implement thecontrol system.

Circuit Details

In FIG. 21 the symbols Y1, Y2, Y3 and so on symbolize test points withinthe circuit. The components in the diagram and their respective valuesare values that work in this particular implementation which of courseis only one of an infinite number of possible design solutions.

Energy to power the circuit is received by the energy receiving coil L1.Energy to implanted components is transmitted in this particular case ata frequency of 25 kHz. The energy balance output signal is present attest point Y1.

Those skilled in the art will realize that the above various embodimentsof the system could be combined in many different ways. For example, theelectric switch 306 of FIG. 21 could be incorporated in any of theembodiments of FIGS. 9-20. Please observe that the switch simply couldmean any electronic circuit or component.

The embodiments described in connection with FIGS. 20 and 21 identify amethod and a system for controlling transmission of wireless energy toimplanted energy consuming components of an electrically operableapparatus. Such a method and system will be defined in general terms inthe following.

A method is thus provided for controlling transmission of wirelessenergy supplied to implanted energy consuming components of an apparatusas described above. The wireless energy E is transmitted from anexternal energy source located outside the patient and is received by aninternal energy receiver located inside the patient, the internal energyreceiver being connected to the implanted energy consuming components ofthe apparatus for directly or indirectly supplying received energythereto. An energy balance is determined between the energy received bythe internal energy receiver and the energy used for the apparatus. Thetransmission of wireless energy E from the external energy source isthen controlled based on the determined energy balance.

The wireless energy may be transmitted inductively from a primary coilin the external energy source to a secondary coil in the internal energyreceiver. A change in the energy balance may be detected to control thetransmission of wireless energy based on the detected energy balancechange. A difference may also be detected between energy received by theinternal energy receiver and energy used for the medical device, tocontrol the transmission of wireless energy based on the detected energydifference.

When controlling the energy transmission, the amount of transmittedwireless energy may be decreased if the detected energy balance changeimplies that the energy balance is increasing, or vice versa. Thedecrease/increase of energy transmission may further correspond to adetected change rate.

The amount of transmitted wireless energy may further be decreased ifthe detected energy difference implies that the received energy isgreater than the used energy, or vice versa. The decrease/increase ofenergy transmission may then correspond to the magnitude of the detectedenergy difference.

As mentioned above, the energy used for the medical device may beconsumed to operate the medical device, and/or stored in at least oneenergy storage device of the medical device.

When electrical and/or physical parameters of the medical device and/orphysical parameters of the patient are determined, the energy may betransmitted for consumption and storage according to a transmission rateper time unit which is determined based on said parameters. The totalamount of transmitted energy may also be determined based on saidparameters.

When a difference is detected between the total amount of energyreceived by the internal energy receiver and the total amount ofconsumed and/or stored energy, and the detected difference is related tothe integral over time of at least one measured electrical parameterrelated to said energy balance, the integral may be determined for amonitored voltage and/or current related to the energy balance.

When the derivative is determined over time of a measured electricalparameter related to the amount of consumed and/or stored energy, thederivative may be determined for a monitored voltage and/or currentrelated to the energy balance.

The transmission of wireless energy from the external energy source maybe controlled by applying to the external energy source electricalpulses from a first electric circuit to transmit the wireless energy,the electrical pulses having leading and trailing edges, varying thelengths of first time intervals between successive leading and trailingedges of the electrical pulses and/or the lengths of second timeintervals between successive trailing and leading edges of theelectrical pulses, and transmitting wireless energy, the transmittedenergy generated from the electrical pulses having a varied power, thevarying of the power depending on the lengths of the first and/or secondtime intervals.

In that case, the frequency of the electrical pulses may besubstantially constant when varying the first and/or second timeintervals. When applying electrical pulses, the electrical pulses mayremain unchanged, except for varying the first and/or second timeintervals. The amplitude of the electrical pulses may be substantiallyconstant when varying the first and/or second time intervals. Further,the electrical pulses may be varied by only varying the lengths of firsttime intervals between successive leading and trailing edges of theelectrical pulses.

A train of two or more electrical pulses may be supplied in a row,wherein when applying the train of pulses, the train having a firstelectrical pulse at the start of the pulse train and having a secondelectrical pulse at the end of the pulse train, two or more pulse trainsmay be supplied in a row, wherein the lengths of the second timeintervals between successive trailing edge of the second electricalpulse in a first pulse train and leading edge of the first electricalpulse of a second pulse train are varied.

When applying the electrical pulses, the electrical pulses may have asubstantially constant current and a substantially constant voltage. Theelectrical pulses may also have a substantially constant current and asubstantially constant voltage. Further, the electrical pulses may alsohave a substantially constant frequency. The electrical pulses within apulse train may likewise have a substantially constant frequency.

The circuit formed by the first electric circuit and the external energysource may have a first characteristic time period or first timeconstant, and when effectively varying the transmitted energy, suchfrequency time period may be in the range of the first characteristictime period or time constant or shorter.

A system comprising an apparatus as described above is thus alsoprovided for controlling transmission of wireless energy supplied toimplanted energy consuming components of the apparatus. In its broadestsense, the system comprises a control device for controlling thetransmission of wireless energy from an energy-transmission device, andan implantable internal energy receiver for receiving the transmittedwireless energy, the internal energy receiver being connected toimplantable energy consuming components of the apparatus for directly orindirectly supplying received energy thereto.

The system further comprises a determination device adapted to determinean energy balance between the energy received by the internal energyreceiver and the energy used for the implantable energy consumingcomponents of the apparatus, wherein the control device controls thetransmission of wireless energy from the external energy-transmissiondevice, based on the energy balance determined by the determinationdevice.

Further, the system may comprise any of the following:

-   -   A primary coil in the external energy source adapted to transmit        the wireless energy inductively to a secondary coil in the        internal energy receiver.    -   The determination device is adapted to detect a change in the        energy balance, and the control device controls the transmission        of wireless energy based on the detected energy balance change    -   The determination device is adapted to detect a difference        between energy received by the internal energy receiver and        energy used for the implantable energy consuming components of        the apparatus, and the control device controls the transmission        of wireless energy based on the detected energy difference.    -   The control device controls the external energy-transmission        device to decrease the amount of transmitted wireless energy if        the detected energy balance change implies that the energy        balance is increasing, or vice versa, wherein the        decrease/increase of energy transmission corresponds to a        detected change rate.    -   The control device controls the external energy-transmission        device to decrease the amount of transmitted wireless energy if        the detected energy difference implies that the received energy        is greater than the used energy, or vice versa, wherein the        decrease/increase of energy transmission corresponds to the        magnitude of said detected energy difference.    -   The energy used for the apparatus is consumed to operate the        apparatus, and/or stored in at least one energy storage device        of the apparatus.    -   Where electrical and/or physical parameters of the apparatus        and/or physical parameters of the patient are determined, the        energy-transmission device transmits the energy for consumption        and storage according to a transmission rate per time unit which        is determined by the determination device based on said        parameters. The determination device also determines the total        amount of transmitted energy based on said parameters.    -   When a difference is detected between the total amount of energy        received by the internal energy receiver and the total amount of        consumed and/or stored energy, and the detected difference is        related to the integral over time of at least one measured        electrical parameter related to the energy balance, the        determination device determines the integral for a monitored        voltage and/or current related to the energy balance.    -   When the derivative is determined over time of a measured        electrical parameter related to the amount of consumed and/or        stored energy, the determination device determines the        derivative for a monitored voltage and/or current related to the        energy balance.    -   The energy-transmission device comprises a coil placed        externally to the human body, and an electric circuit is        provided to power the external coil with electrical pulses to        transmit the wireless energy. The electrical pulses have leading        and trailing edges, and the electric circuit is adapted to vary        first time intervals between successive leading and trailing        edges and/or second time intervals between successive trailing        and leading edges of the electrical pulses to vary the power of        the transmitted wireless energy. As a result, the energy        receiver receiving the transmitted wireless energy has a varied        power.    -   The electric circuit is adapted to deliver the electrical pulses        to remain unchanged except varying the first and/or second time        intervals.    -   The electric circuit has a time constant and is adapted to vary        the first and second time intervals only in the range of the        first time constant, so that when the lengths of the first        and/or second time intervals are varied, the transmitted power        over the coil is varied.    -   The electric circuit is adapted to deliver the electrical pulses        to be varied by only varying the lengths of first time intervals        between successive leading and trailing edges of the electrical        pulses.    -   The electric circuit is adapted to supplying a train of two or        more electrical pulses in a row, said train having a first        electrical pulse at the start of the pulse train and having a        second electrical pulse at the end of the pulse train, and    -   the lengths of the second time intervals between successive        trailing edge of the second electrical pulse in a first pulse        train and leading edge of the first electrical pulse of a second        pulse train are varied by the first electronic circuit.    -   The electric circuit is adapted to provide the electrical pulses        as pulses having a substantially constant height and/or        amplitude and/or intensity and/or voltage and/or current and/or        frequency.    -   The electric circuit has a time constant, and is adapted to vary        the first and second time intervals only in the range of the        first time constant, so that when the lengths of the first        and/or second time intervals are varied, the transmitted power        over the first coil are varied.    -   The electric circuit is adapted to provide the electrical pulses        varying the lengths of the first and/or the second time        intervals only within a range that includes the first time        constant or that is located relatively close to the first time        constant, compared to the magnitude of the first time constant.

While specific embodiments of the invention have been illustrated anddescribed herein, it should be realized that numerous other embodimentsmay be envisaged and that numerous additional advantages, modificationsand changes will readily occur to those skilled in the art withoutdeparting from the spirit and scope of the invention. Therefore, theinvention in its broader aspects is not limited to the specific details,representative devices and illustrated examples shown and describedherein. Accordingly, various modifications may be made without departingfrom the spirit or scope of the general inventive concept as defined bythe appended claims and their equivalents, and numerous otherembodiments may be envisaged without departing from the spirit and scopeof the invention.

1-57. (canceled)
 58. A method for controlling a medical implant systemin a mammal body, the system comprising a first and a second part beingadapted for communication with each other, in which system the firstpart is adapted for implantation in the mammal body for the control ofand communication with the medical implant, the second part is adaptedto be worn on an outside of the mammal body in physical contact withsaid body and adapted to receive control voice commands from a user andto transmit these commands to the first part, the method comprising thesteps of: using the mammal body as a conductor for the communicationbetween the first and the second parts, receiving and recognizing by thesecond part the control commands from a user as voice commands,transforming recognized voice commands into signals which aretransmitted to the first part via the mammal body as a conductor for thecontrol of said implant, conveying such signals to the implant by thefirst part, and translating voice commands comprising a complex ofdifferent frequencies into one fixed defined output command by thesecond part, wherein the system comprises a first conducting plate inthe first part of the system and a second conducting plate in the secondpart of the system, and the method further comprises the step ofcreating an electrical capacitive field with potential differencesbetween said first and second conducting plates using the mammal body asthe conductor.
 59. The method of claim 58, comprising a detector circuitat least in the first part of the system, the method comprising thesteps of: detecting potential differences between the conducting plates,and using the potential differences for said communication between thefirst and the second parts of the system.
 60. The method according toclaim 58, comprising a first and second conducting plate in each of thefirst and second parts of the system, the method further comprising thesteps of: creating an electrical field with potential differencesbetween the first and second conducting plates in the second part of thesystem, the system further comprising a detector circuit in the firstpart of the system, detecting variations in the potential difference inthe first and second conducting plates, thereby communicating betweenthe first and the second parts, and using the potential differences forthe communication between the first and the second parts of the system.61. The method according to claim 60, in which at least one of the firstand second conducting plates in each of the first and second parts ofthe system is covered by a dielectric material.
 62. The method accordingto claim 58, wherein each of the first and second parts comprises acomparator for comparing at least two different received frequencies,the method further comprising the step of comparing at least twodifferent received frequencies as part of the communication between thefirst and second parts.
 63. The method according to claim 58, in whichsaid system comprises an ornament such as a necklace, a bracelet, aring, an ear ring or a piercing ornament for the human body.
 64. Themethod according to claim 58, in which said system comprises a watch ora wrist watch.
 65. The method according to claim 59, wherein the stepsof detecting the potential differences between the conducting plates,and using the potential differences for said communication between thefirst and the second parts of the system, further comprises the stepsof: creating the capacitive electrical field with potential differencesbetween said plates, so that the communication between the first andsecond parts can be in either direction, allowing both of the first andsecond parts to be either a sending part or a receiving part, in whichsystem the second part comprises a detector circuit for detecting saidpotential difference, wherein the method further comprises the steps of:interpreting the detected potential differences as said communication,and presenting to the user, by the second part, received communicationsfrom the first part.
 66. The method according to claim 65, the methodfurther comprising the steps of: creating and sending at least twodifferent signal frequencies in the electrical field by the sendingpart, receiving and detecting which frequency is being received from theelectrical field, using a detector circuit in the receiving part, andinterpreting these at least two frequencies as the communication betweenthe two parts.
 67. The method according to claim 65, the methodcomprising the further steps of: creating pulses with positive andnegative amplitudes in the electrical field in the sending part, anddetecting said pulses with positive and negative amplitudes, andinterpreting these amplitudes as the communication between the two partsby the detector circuit of the receiving part.
 68. The method accordingto claim 58, the method comprising the further step of reducing theelectrical current which flows in the mammal body by using a highelectrical resistance between the first and second parts of the system.69. The method according to claim 68, wherein the electrical resistanceis at least 1 Mega Ohm.
 70. The method according to claim 58, in whichat least one of the first part and the second part comprises acommunication transceiver comprising at least a part of a capacitiveenergy storage, the method further comprising the step of injecting ordrawing an electrical current into or from the capacitive energy storageusing the capacitive field for the communication.
 71. The methodaccording to claim 70, in which the second part comprises thecommunication transceiver, the second part further comprises a secondpart of a capacitive energy storage, the method further comprising thestep of: injecting or drawing an electrical current into or from acapacitive energy storage using the capacitive field for thecommunication.
 72. The method according to claim 58, in which thecommunication between the first and second parts is performed digitally,the method further comprising the step of representing the informationby variations of the derivative of the voltage over the capacitiveenergy storage.
 73. The method according to claim 70, in which each ofthe first and second parts of the capacitive energy storage is dividedinto two separate portions, the method further comprising the steps of:injecting or drawing an electrical current into or from one of the twoseparate portions, simultaneously, and injecting or drawing anelectrical current into or from, respectively, the other of the twoseparate portions.
 74. The method according to claim 58, the systemcomprising at least one switch implantable in the patient for manuallyand non-invasively controlling the system, and a wireless remote controlfor non-invasively controlling the system, the method further comprisingthe step of non-invasively controlling the apparatus by at least one ofthe wireless remote control and the implantable switch.
 75. The methodaccording to claim 58, the system comprising at least one of: aninternal energy source for powering implantable energy consumingcomponents of the system, and an internal energy receiver, adapted to beenergized non-invasively and wirelessly by an energy transmission devicefrom outside the patient's body, the method further comprising the stepsof sending wireless energy to at least one of: the implantable internalenergy source when comprised in the system, being chargeable by energytransferred from an energy transmission device, and the internal energyreceiver when comprised in the system, supplying energy to at least oneimplantable energy consuming component of the system, being energised bythe wireless energy.
 76. The method according to claim 58, wherein thesystem comprises a sensor and/or a measuring device, the method furthercomprising the steps of sensing or measuring at least one of: at leastone physical parameter of the patient, and at least one functionalparameter related to the system, the functional parameter comprising atleast one of: a functional parameter correlated to the transfer ofenergy for charging an internal energy source, and a functionalparameter related to the system, sending feedback information using afeedback device from inside the patient's body to at least one of: animplantable internal control unit comprised, and an external controlunit outside of the patients body, via the internal control unit,wherein the internal control unit being adapted to be programmed toregulate the system according to a pre-programmed time-schedule or toinput from any sensor sensing any possible physical parameter of thepatient or any functional parameter of the system, and wherein thefeedback information being related to at least one of: the at least onephysical parameter of the patient, and the at least one functionalparameter related to the system.
 77. The method according to claim 58,wherein said second part comprises a learning device adapted tosuccessively learn the voice commands and learn to combine with theright output command, the method further comprising the steps of:learning the voice commands and learning to combine with the rightoutput command, recognizing by the learning device to approximate voicecommands into a fixed defined output command, wherein said voicecommands comprise a complex of different frequencies, translating thevoice commands into one fixed defined output command, and summarizing adefined input of different frequencies into one single action, whereinsaid output commands do not differentiate different frequencies.